πŸ”§Wi-Fi Channel Tool (wifichannel)

you can think of this as a warm up exercise

WLAN Pi comes with a small CLI tool called wifichannel

This tool began as a simple conversion utility, for switching between channel numbers and centre frequencies.

Channel maths

Query wifichannel with the command

wifichannel 7

The output gives you information about channel 7

wifichannel 6
wifichannel 17
wifichannel 60
wifichannel 6055

List all channels

Display all 2.4 GHz channels:

wifichannel -2

Display all 5 GHz channels:

wifichannel -5

How would you display all 6 GHz channels?

This command will help you if you are ever in doubts:

wifichannel -h

Note the Lower 6 GHz and Upper 6 GHz channels. In Czech Republic and most of Europe, we can only use the Lower 6 GHz channels.

Filter output with Linux filters (grep)

You can filter the output of most command line utilities to make the output more efficient.

Example

How many channels in the 2.4 GHz band are 'recommended'?

First, run the command to display all 2.4 GHz channels:

wifichannel -2

You could count the lines manually, but there is no need. Computers can already do that, really fast.

Using a linux utility called grep we can filter the output to only include lines that contain "a particular string or pattern":

wifichannel -2 | grep "Recommended: Yes"

Be precise with your search terms (strings), capitalisation matters.

Finally, we can simply count the number of lines returned by the command using word count, that command looks like this:

wifichannel -2 | grep "Recommended: Yes" | wc -l

The wc command has nothing to do with restrooms πŸ˜‰ It stands for "word count" and its "l" parameter stands for lines.

Last updated